Black box is a common name for a device installed in a transport to record information. For example, the black box may include recorders for all kinds of transports, such as a flight data recorder (FDR), a voyage data recorder (VDR), and an event data recorder (EDR).
The FDR is installed in an aircraft to record conditions of the aircraft, audio information in the cockpit, audio information of communications, etc. The VDR is installed in a ship to record operation conditions of various nautical instruments, contents transmitted and received by a communication device, video or audio information in the wheelhouse, etc. Further, the EDR is installed in a car or a bicycle to record video information recording inside and outside of the vehicle and audio information recording sounds in the vehicle in case of an accident.
Image data recorded from a black box have been used as an important evidence in analyzing an accident or crime. However, the image data can be easily modulated using an editing tool. Particularly, with the advancement of editing technology using editing tools, image data modulated using a recently developed editing tool cannot be recognized with the naked eye. Accordingly, techniques for guaranteeing integrity of image data and easily detecting modulation are being developed.
In particular, the Korean Agency for Technology and Standards established the KS black box standards, KS-R-5078 (entitled “Image-based accident recorder for vehicle”), in June 2011 to recommend a black box to be equipped with a system that guarantees integrity of data and detects modulation.
Examples of conventional methods for guaranteeing integrity of image data may include a method of inserting a digital watermark into image data and a method of calculating a hash value of image data using a hash function and storing the hash value with the image data.
In this regard, Korean Patent No. 10-1593008 (entitled “Method and system for generating integrity verification data”) discloses a method and a system for verifying integrity of image data by applying a logical operation to a hash value for each of blocks included in the image data.